Or HaChaim on Deuteronomy 23:25/אור החיים על דברים כ״ג:כ״ה

1 ואל כליך לא תתן, "but you may not put any of them into your vessel." The Torah prefaces the word כליך with the conjunctive letter ו to remind us that there was another commandment which immediately preceded this commandment. We refer to the prohibition to overeat from the grapes of the vineyard of your employer. We derive this prohibition from the fact that the Torah wrote שבעך "to your satisfaction," i.e. not more than your fill. After this the Torah added: "neither shall you put any into your vessel."